Research on the biology of the periodontium of various primate species from man to marmosets will be performed in a coordinated multidisciplinary program. The target is the control of human periodontal disease through an understanding of the basic disease processes. The basic objective of the program-project is the study of the periodontium as a biological unit in health and disease. Multidisciplinary and interdisciplinary experiments are designed to elicit the responsiveness of the periodontium to changes in its biological environment. A three-pronged interdisciplinary attack on the problems of periodontal disease, designed to establish the manner in which (I) environmental factors, (II) conditioning factors and (III) mediating factors interact to produce inflammatory periodontal disease in man and other primates has been developed. Thus, a solution to the complex health problem, periodontal disease, is being sought through coordinated research on multiple and interdisciplinary aspects of the problem. The effectiveness of the program is critically dependent upon the contribution of each member of the research team. The disciplines represented are: bacteriology, biochemistry, electron microscopy, histology, immunology, immunopathology, nutrition, oral physiology and virology.